Keywords: linear regression with two groups, analysis of covariance
The following data was collected in the 1960s at a house in south-east England. The weekly gas consumption (in 1000 cubic feet) and the average outside temperature (in degrees Celsius) was recorded for 26 weeks before and 30 weeks after cavity-wall insulation had been installed. The house thermostat was set at 20°C throughout.
|Insulate||Before or After|
|Temp||Average outside temperature (°C)|
|Gas||Gas consumption (1000's of cubic feet)|
Data File (tab-delimited text)
I don't have the source recorded - please remind me if you know.